Strong emotion and excellent performances make Beautiful Boy compelling despite its dreary-sounding premise: parental grief at the death of a child.

Comfortable middle-class couple Kate (Maria Bello) and Bill (Michael Sheen) are on the verge of breaking up. Neither one is a monster; they just don't communicate at all. When their freshman son, Sam, dies abruptly, they collapse.

Bello and Sheen deliver the full spectrum of grief with flawless naturalism. They move through numbness, denial, anger, false stoicism, obsessive behaviour and, above all, guilt. They feel responsible for Sam's death and can barely face it. Beneath that are the festering resentments of their marriage.

Writer/director Shawn Ku keeps this from bogging down with a string of plausible events and a near-documentary style that chops up single-take scenes to create rhythm and avoid predictability. The director, cinematographer and editor do an okay job of examining their creative choices on the commentary, but Ku wastes time explaining subtext that we're perfectly capable of discerning ourselves.